Brake adjustment



April 28, 1931.

J. T. WARD 1,802,797

BRAKE ADJUSTMENT Filed Feb. 26, 1929 W TTQRNEY Patented Apra 28, 1931 PATENTi OFFICE JAMES T. WARD, 015 LOS ANGELES, CALIFORNIA.

BRAKE ADJUSTMENT- Application filed February 26, 1929. Serial No. 342,726.

This invention relates to vehicle brakes and more especially to internal, expansion brake shoes of vehicle wheels.

Hydraulic brake shoes as now extens1vely used in motor vehicles are pivotally mounted on anchor pins at one of their ends and the opposite end, of a shoe, is expanded, by a plston from a spring retracted position. As the brake lining wears the shoe is bodily adjusted toward the wheel drum.

This adjustment necessitates two independent operations; first the turning of the anchor pin so that an eccentric thereon will shift the lower end of the shoe and, second, the adjustment of a cam device or back rest to move the swinging end of the shoe outward. These two operations require considerable time in loosening and setting of the binding nuts and screws; require very care- :tul gaging to obtain equal brake pressure along the shoe. Each end of the shoehas its own isolated, unrelated adjustment device, separately manipulated.

An object of the present invention is to provide for the simultaneous, uniform adjustment of each end of the brake shoe and thereby to eliminate one of the two operations above described. In other words an object is to effect the adjustment of the shoe to the desired position by a single manual opera tion.

A further object is to simplify the shoe adjusting operation and means -for accomplishing the adjustment, and to provide a single, manually operable, control member in a mechanism actuating each end ofa shoe.

And an object is to provide an index means fir facilitating accurate adjustment of the s cc.

Additional objects, advantages and features of construction and combination, and the mode of operation will be made manifest in the ensuing description of the herewithillust-rative embodiment; it being understood that modifications, variations and adapta= tions may be resorted to within the spirit, scope and principle of the invention as it is hereinafter claimed.

Figure 1 is a wheel-side elevation of a brake shield showing the applied adjusting device, and a part of a brake shoe.

Figure 2 is an inside elevation of the shield, with index dials.

Figure 3 is a diametrical section of the shield, showing the master, adjustable anchor pin.

Figure 4 is a detail of the adjusting cam for the swinging end of the shoe.

Figure 5 is an end view of the master adjusting pin.

A brake shoe 2 is here shown as having one end journaled on an eccentric 3 formed on an anchor pin 4 which is turnably mounted in a brake shield 5. By rotating the pin 4 the lower end of the shoe is adjusted toward or from a brake drum (not shown).

A feature of the present invention is to adjust the shoe bodily laterally through the medium of a single master device.

For this purpose the pin 4; is provided with an eccentric 10 set from the eccentric 3, in the present .case, and on this is mounted a rod 11 having an intermediate turn-buckle 12 for accurate-setting, and having on its remote end a wedge block A interposed between a solid abutment 14, on the shield 5, and a stop pin B fixed on the adjacent end of the shoe 2, which, in thepresent disclosure, is expanded by a hydraulic piston 16.

A spring 17 normally retracts the shoe against the adjustable block A which in turn is supported by its rest 14.

For the purpose of preventing rattling of the adjusting rod 11 a spring 18 is interposed between the abutment 14 and the head of a screw 19 passing through a slot 20 in the abutment and engaging the adjuster block A so that this is always held firmly but slidably to its rest.

When it is desired to adjust the shoe to take up wear a lock nut 6 on the pin 4 is backed away to release the pin and a tool is applied to its flat end 4;. Rotation of the pin will through the eccentric 3 shift the lower end of the shoe 2 and at the same action the eccentric 10 will shift the adjusting rod 11 endwise and press the wedge block A upward between the stop pin B, on the shoe, and the rest 14 with the result that the top of the shoe will shift laterally concurrently with lateral shift of the bottom of the shoe.

As soon as adjustment has been made'the lock nut 6 is set up tight to secure the anchor pin 4 to the shield 5.

A further advantageous feature consists of means to facilitate the very accurate adjustment of the brakeshoe. The pin 4 has keyed thereon a pointer 7 and this operates over a fixed dial 8 on the shield 5 during rotations of the master pin 4.

In practice the shoe is set bodily true and hard against its drum by the adjusting device and then by reversing the action of the pin 4 the shoe can be drawn back to clear the drum by as much space as desired. The indicator is calibrated to show the amount of clearance from the drum. n

What is claimed is: I

1. In a drum, brake apparatus, a brake shoe and a pivot on which one end of the shoe is mounted, and, adjusting means for bodily laterally shifting the shoe in a single adjusting action.

2. In a brake apparatus, a shoe pivoted on one end, and a master adjusting means, Operative in one action, to bodily shift the shoe toward or from its drum.

3. In a brake apparatus, a shoe, a pivot pin on which one end of the shoe is mounted, a back stop for the opposite end of the shoe, and means for concurrently laterally adjusting each end of the shoe, and including eccentrics on said pin.

4. In a brake apparatus, a shoe, adjustable supports for each end of the shoe, and means for concurrently actuating the supports to laterally, bodily shift the shoe.

5. In a brake apparatus, a shoe, adjusting supports for each end of the shoe and a single master device for actuating said supports cfincurrently to bodily, laterally adjust the 5 0e.

6. In a brake apparatus, a shoe, an eccentric on which the shoe is pivoted, an adjusting device for the opposite end of the shoe, and

a master member operatively combined with said eccentric and said device to concurrently actuate them to adjust the shoe.

7. A brake shoe, a pin having an eccentric on which the shoe is pivoted, and an adjustng device mounted on said pin and supportmg the opposite end of the shoe; said pin operative to actuate said eccentric and device to adjust the shoe.

JAMES T. WARD. 

